Project Summary/Abstract Shared decision making (SDM) is growing in clinical and political importance. Based on a large Cochrane review, the science supporting the assertion that patient decision aids (PtDAs) result in SDM and improve decision outcomes is strong. However, the benefits of real-world use of PtDAs remains unrealized as PtDAs are largely unused in routine health care. Previous attempts at real-world implementation of PtDAs have been characterized by a focus on low-risk decisions in primary care. The problem with this approach is that, since the stakes are so low, busy clinicians perceive PtDAs to be of little value, undermining their implementation. This team's overall goal is to assess real-world effectiveness (Aim 1) and implementation (Aim 2) of patient decision aids (PtDA) for high-risk decisions using the implantable cardioverter-defibrillator (ICD) as a model. ICDs are ideal to study because they are common and involve complex trade-offs. While they can prolong lives, they do not improve quality of life (QOL) and come with a host of risks including device failure, inappropriate shocks, shocks (and subsequent suffering) at the end of life, anxiety, depression, and post- traumatic stress disorder. While most patients see prevention of sudden death as desirable, they also prefer to die peacefully in their sleep (which the ICD would try to prevent). In recognition of the personal nature of ICDs, professional guidelines now recommend SDM for eligible patients. This proposal addresses two big problems: 1) a lack of effectiveness data for PtDAs in real world settings, as efficacy trials comprise virtually all of the data supporting PtDAs; and 2) the optimal implementation strategy for PtDAs is unknown. This team has developed a reproducible, sustainable, low-cost strategy to facilitate implementation across diverse clinical settings. This application proposes the DECIDE-ICD trial: a type II effectiveness implementation hybrid trial of three ICD PtDAs. The DECIDE-ICD trial is a 6-site stepped-wedge randomized trial, with implementation guided by normalization process theory and a mixed methods evaluation guided by the RE-AIM framework. The study team has the relationships, infrastructure, and transdisciplinary expertise to execute this project. By simultaneously exploring effectiveness and implementation, this project will provide pragmatic information that will inform a growing national agenda to better involve patients in their health care via SDM.